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by mwrich4
Sun Jul 12, 2020 8:19 pm
Forum: Automation, sensing and robotics
Topic: Multiple Automated Syringe Motors
Replies: 5
Views: 212

Re: Multiple Automated Syringe Motors

I used a separate board for my GUI with macro-control and sent low-level commands to an autonomous motor controller via an RS-485 board network bus. The Pi or Arduino may simply be the microcontroller in his project. Driving motors requires an RTOS (or another lean environment) if you don't want a v...
by mwrich4
Thu Jul 09, 2020 2:29 pm
Forum: Advanced users
Topic: Network (Ethernet) Boot for Pi4
Replies: 13
Views: 1992

Re: Network (Ethernet) Boot for Pi4

Ethernet boot is weeks away maybe a month for general beta. It’s approaching feature complete but lots of debug/test left to do. General firmware stability issues are still higher priority than advanced boot modes. Anyway the first boot related thing will be the beta EEPROM updated apt package. The...
by mwrich4
Thu Jul 09, 2020 3:32 am
Forum: Graphics, sound and multimedia
Topic: Looking To Build Internet Radio Stream Receiver
Replies: 19
Views: 3321

Re: Looking To Build Internet Radio Stream Receiver

mwrich4 wrote:
Tue Dec 31, 2019 8:42 pm
I found an article that pointed out the URL strings are in the page source for the iHeart web interface.

https://c3.prod.playlists.ihrhls.com/4426/playlist.m3u8
https://c3icy.prod.playlists.ihrhls.com/4426_icy
Sadly, iHeart has now discontinued these stream sources.
by mwrich4
Wed Jul 08, 2020 8:35 pm
Forum: Off topic discussion
Topic: An observation...NOT a prediction and NOT a "wish list"
Replies: 24
Views: 745

Re: An observation...NOT a prediction and NOT a "wish list"

I've got a desktop linux box here with 16GB RAM, never get remotely close to using it up. My windows PC has 32GB ... But would you use the Pi4 for it? Could Mythicbeasts make cost effective use of it, for example. [offtopic] Using a RPi is not close to using my i7, for me anyway. Having EVERYTHING ...
by mwrich4
Wed Jul 08, 2020 8:02 pm
Forum: C/C++
Topic: Get Reading from ADS1115
Replies: 45
Views: 3154

Re: Get Reading from ADS1115

This would be a great time to familiarize yourself with the datasheet for that part since you have an understanding now.

Firmware for bare metal programming nearly requires that you can decipher the interface protocols from a datasheet when you can't find or debug example code for your part.
by mwrich4
Wed Jul 08, 2020 7:35 pm
Forum: Off topic discussion
Topic: An observation...NOT a prediction and NOT a "wish list"
Replies: 24
Views: 745

Re: An observation...NOT a prediction and NOT a "wish list"

I'd like to observe that there are currently no 16GB chips that would fit. This was said about 8GB. And although we've had a couple of people asking for 16GB, why on EARTH would you need that much memory on a limited CPU device like the Pi4. "No one would EVER need more that 640k" I've got a deskto...
by mwrich4
Wed Jul 08, 2020 7:18 pm
Forum: Advanced users
Topic: Network (Ethernet) Boot for Pi4
Replies: 13
Views: 1992

Re: Network (Ethernet) Boot for Pi4

Since the Mythic Beasts blog a few days ago, does the mean network boot is moving from beta soon?

Is it reliable enough for userland to start tinkering with it?
by mwrich4
Wed Jul 01, 2020 5:33 am
Forum: Beginners
Topic: Problem measuring capacitor discharge time using GPIO pins
Replies: 7
Views: 278

Re: Problem measuring capacitor discharge time using GPIO pins

doing this seems straightforward, but gpio will not wait until 0 volts to show off or 3.3(5.0) to show high. They are digital inputs, plus depending on your port configuration, the Input pin could charge your cap if you had it configured for pull-up for example. Use an oscilloscope to monitor what i...
by mwrich4
Sun Jun 28, 2020 11:14 pm
Forum: Troubleshooting
Topic: Boot fro SSD options
Replies: 14
Views: 539

Re: Boot fro SSD options

be sure to try a standard 1920x1200 monitor. I had a smaller one that didn't work for Rpi 4, but did for Rpi3. Wasted a day...
by mwrich4
Tue May 05, 2020 5:50 am
Forum: General discussion
Topic: USB LED Controller (NOT LED STRIPS)
Replies: 20
Views: 603

Re: USB LED Controller (NOT LED STRIPS)

Adafruit has at least one widget that provides a serial port and several GPIO ports for a cheap price. It connects via USB.

To give you an idea: https://www.adafruit.com/product/3191.

You could add a couple of hex-inverters to increase the current capability for each circuit.
by mwrich4
Tue May 05, 2020 5:41 am
Forum: C/C++
Topic: How much memory in C
Replies: 25
Views: 1256

Re: How much memory in C

If it is very large perhaps the malloced memory has been swapped out. This is a common issue in Windows and you have to take extra steps to ensure the memory is flagged as persistent(non-swappable). I hope that's not the case. If memory that's been been swapped or paged out is accessed, the system ...
by mwrich4
Tue May 05, 2020 5:39 am
Forum: Automation, sensing and robotics
Topic: How to make a "robot" to go back to a point ?
Replies: 10
Views: 587

Re: How to make a "robot" to go back to a point ?

Some cell phones like my Samsung Galaxy S5 don't block IR from the camera. They can see remote control LEDS. Great for verifying good batteries vs broken remote.

If you turn off the room lights you can get a good idea of relative brightness and any strong reflections.
by mwrich4
Sat May 02, 2020 6:00 pm
Forum: Advanced users
Topic: Raspberry Pi4 fail in the very moment I connect a second hard drive
Replies: 14
Views: 1424

Re: Raspberry Pi4 fail in the very moment I connect a second hard drive

I have a 3A 5V supply on my RaspPi. I plug my Samsung S5 into a Pi USB port for charging every day at USB 2.0 charging level. Invest in a good Pi Supply and use alternate supplies for other HHDs because they generate periodically HIGH loads. A number of SSDs should be ok directly on the Pi, but the ...
by mwrich4
Sat May 02, 2020 5:51 pm
Forum: Automation, sensing and robotics
Topic: How to make a "robot" to go back to a point ?
Replies: 10
Views: 587

Re: How to make a "robot" to go back to a point ?

It would require accurate tracking of wheel movement and wheel path mapping memory. Then you calculate your path to return. Most inexpensive robot kits don't offer accurate tracking for the wheel motion without a fair amount of extra money for the wheel sensors. I don't think GPS would offer enough ...
by mwrich4
Sat May 02, 2020 5:43 pm
Forum: C/C++
Topic: How much memory in C
Replies: 25
Views: 1256

Re: How much memory in C

The Pi has a lot of memory. Unless you are doing something really LARGE it's more likely that there's a pointer mistake. If it is very large perhaps the malloced memory has been swapped out. This is a common issue in Windows and you have to take extra steps to ensure the memory is flagged as persist...
by mwrich4
Sat May 02, 2020 5:32 pm
Forum: Advanced users
Topic: [Resolved] Help with a Serial Mouse
Replies: 14
Views: 485

Re: Help with a Serial Mouse

Why would you do this to yourself? A decent USB mouse is available for under $5 and they're optical so much more robust.
by mwrich4
Sat May 02, 2020 5:29 pm
Forum: General discussion
Topic: Music Player Server Possible with Mpd and RPI?
Replies: 7
Views: 489

Re: Music Player Server Possible with Mpd and RPI?

Study the implementation of Volumio OR just use that. Mine has been running 24/7 for almost 3 months now. I use it to stream iHeart, but it can play from local or NAS storage.
by mwrich4
Fri Apr 24, 2020 6:18 pm
Forum: General discussion
Topic: Raspberry Pi 4 2GB 1.2 version
Replies: 25
Views: 1643

Re: Raspberry Pi 4 2GB 1.2 version

Question: Why was a change made on the board build and the silk-screen NOT updated? We never do that, it leads to trouble.

Edit: Funny, there were silk screen changes on the bottom, but no Rev listed anywhere.
by mwrich4
Fri Apr 24, 2020 6:10 pm
Forum: HATs and other add-ons
Topic: When will someone release a Raspberry Pi 4B UPS HAT with Battery Backup?
Replies: 5
Views: 3165

Re: When will someone release a Raspberry Pi 4B UPS HAT with Battery Backup?

Wouldn't using a battery brick between the RaspPi and the power supply be more cost-effective? The Pi draws so little it shouldn't overload the power supply. If covering a long outage isn't needed, a lower capacity would save some money. Overall, I think a battery brick that offers good charging dis...
by mwrich4
Tue Apr 21, 2020 12:15 am
Forum: General discussion
Topic: How can I use GPS with Serial while another sensor use it
Replies: 14
Views: 557

Re: How can I use GPS with Serial while another sensor use it

In other projects, I have used a buffer chip to toggle between 2 or more serial paths. It's an extra layer for your code, but aside from the toggle everything else works the same.
by mwrich4
Tue Apr 21, 2020 12:00 am
Forum: Troubleshooting
Topic: Wrong supply voltage (12Vdc) and now what can i do?
Replies: 31
Views: 972

Re: Wrond supply voltage (12Vdc) and now what can i do?

LTolledo wrote:
Fri Apr 17, 2020 8:56 pm
its bye bye RPi for you....

my usual advice for this:
put the dead RPi in a picture frame
put a good title for the framed RPi (ie. "in memoriam RPi vs 12v")
and display it on your workshop
Bonus points for encasing in resin. Like it's preserved in Amber.
by mwrich4
Mon Apr 20, 2020 11:53 pm
Forum: Other programming languages
Topic: COBOL on the Pi.
Replies: 15
Views: 3397

Re: COBOL on the Pi.

My curiosity is piqued. COBOL offered many platform-specific methods for IO via Linkage or system calls. I'd be surprised if the Linux version doesn't have any. PC variants from the solo DOS days had ways to do these things. ( REALIA ) It doesn't surprise me that you may need to run as root unless y...
by mwrich4
Thu Apr 09, 2020 6:19 am
Forum: Beginners
Topic: Multi-drop bus and RPi
Replies: 14
Views: 6375

Re: Multi-drop bus and RPi

RS485 is the electrical format. MDB implementation can vary without more specs. 9-bit is common for microcontrollers using CANBUS or similar. MDB doesn't need a dedicated master, but that depends on the implementation of the particular protocol. If you don't have system specs, successful communicati...
by mwrich4
Fri Apr 03, 2020 5:30 am
Forum: Bare metal, Assembly language
Topic: Making the Raspberry PI Model B+ 4 Run Assembly Bare
Replies: 15
Views: 1419

Re: Making the Raspberry PI Model B+ 4 Run Assembly Bare

FWIW, running bare metal projects is not a friendly place.

If you don't own at least an oscilloscope, you may want to work up from simple bare metal projects on an Arduino, get familiar with the level of details and build a set of skills and tools to help you become proficient on the RasPi.
by mwrich4
Tue Mar 31, 2020 11:18 pm
Forum: Beginners
Topic: Little knowledge, just an idea, need a learning starting point
Replies: 5
Views: 291

Re: Little knowledge, just an idea, need a learning starting point

Truly erasing flash take TIME.

If this is a panic mode ability, I suppose it's technically viable with another small autonomous processor. But it's a LOT of design work as stated above.

Otherwise, most of us just insert and delete in a system.

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